Start removing MASTER_SITE_SUBDIR=CPAN:username where possible. The
downside to having this set is that portscout cannot find new releases
when the username changes (which happens often in large projects with
multiple maintainers).

Change the way Perl modules are installed, update the default Perl to 5.18.
Before, we had:
site_perl : lib/perl5/site_perl/5.18
site_perl/perl_arch : lib/perl5/site_perl/5.18/mach
perl_man3 : lib/perl5/5.18/man/man3
Now we have:
site_perl : lib/perl5/site_perl
site_arch : lib/perl5/site_perl/mach/5.18
perl_man3 : lib/perl5/site_perl/man/man3
Modules without any .so will be installed at the same place regardless of the